Weight painting issues
To see all the bones influencing geometry:


Select the mesh.
Get into Edit Mode.
Select the vertices you're interested in.
Hover your cursor over the 3d Viewport, hit N.
Scroll down until you see Vertex Weights.




From there, select the Deform option and you should be able to see all the influences.  If there's an influence that you don't want there, hit the X next to the VG name.